Untreated substance use disorders are associated with premature mortality, productivity loss, high rates of disability, and increased risk for HIV. Substance use also places users at risk for elevated depression symptoms and high levels of anxiety. In reciprocal fashion, having mental health problems radically increases the likelihood of augmented drug use, smoking, binge drinking and heavy episodic drinking. Despite a substantial body of evidence documenting the high prevalence of dual-diagnosis patients, few rigorous interventions have been conducted to treat individuals with comorbid substance use and mental health disorders. Globally, most people with substance use and/or mental health problems receive no treatment. The proposed International Latino Research Partnership (ILRP) directly responds to this gap in the literature. The ILRP brings together research institutions an their partnering community clinics in Boston, Madrid and Barcelona to enhance a collaborative international partnership and to develop the research evidence necessary to respond to Latino migrants' behavioral health service needs. We turn our focus to Latino migrants because economic opportunities have moved unprecedented numbers of migrants from Latin America to host countries like Spain and the US. Spain has the second largest number of Latino migrants in the world behind only the US, where most immigrants are Latino. Migrant Latinos confront colossal barriers to behavioral health. During the process of acculturation to the host culture, migrants have been shown to drink more alcohol and use more drugs straining the health care system, public safety, and increasing their risk for HIV. We propose three aims: 1) Develop an international partnership and research collaboration to support research that can improve accessibility, quality and outcomes of integrated behavioral health services for migrant Latinos with co-occurring substance use, mental health problems and/or HIV risk in primary care clinics; 2) Harmonize data across research sites; and 3) Conduct behavioral health services research focused on rapid screening, referral, and integrated behavioral health services research for migrant Latino populations with co-occurring substance use, mental health problems, and HIV risk in primary care clinics. For Aim 3, we follow a Screening, Brief Intervention and Referral to Treatment (SBIRT) model, where we first test the validity of a brief behavioral health screener for Spanish-Speaking populations. Building on that work, we test the feasibility, acceptability and efficacy of the Integrated Intervention for Dual Problems and Early Action (IIDEA) intervention addressing substance use, smoking and mental health disorders. As such, the proposed ILRP multi-site international project is a critical step towards developing models of integrated care for the large and diverse Latino migrant population and more broadly towards understanding how best to integrate evidence- based assessment and treatments for co-occurring substance and mental health problems and HIV risks.